The authoritative public forum
  for Metal Finishing since 1989
-----

Silver Turns Copper After Polishing

2007

Hello -
I bought a bracelet on eBay that was represented as 925 sterling. It arrived quite tarnished and stamped 925. After polishing, the silver turned almmost entirely copper. When contacted, the seller asked what testing method I used. Is it necessary to do an acid test when you can simply look at it and see the copper?
Thanks!

Gail Weinflash
hobbyist - Lewisville, Texas

---

Hello Gail,
If it is stamped .925 it "should" be sterling silver. The 7.5% copper content in the make-up of sterling is not enough to change the whole appearance of the object after polishing, unless the wrong polish was used. It sounds to me it's silver plating over copper. When the piece was polished it wore off the silver plate and the copper was exposed. How are you going to test for silver when there is none there? Try to get your money back.

Mark Baker
Process Engineer - Syracuse, New York
2007

---

I'd concur with that, Mark. If it looks like a duck, walks like a duck, and quacks like a duck, you don't need a duck test to justify to the seller that it's a duck :-)

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007